Patent GB-599056-A (GB)
Title: Ultra-short-wave signal-translating electron discharge apparatus incorporating cavity resonator circuits
IPC: H03F3/54
Filed: 1945-10-30
Abstract: 599,056. High-frequency discharge apparatus; electric resonators. HAZELTINE CORPORATION. Oct. 30, 1945, No. 28812. Convention date, Nov. 30, 1944. [Classes 39 (i) and 40 (iii)] An ultra-short wave signal-translating device comprises a cavity resonator 10, Fig. 1, conductive means such as a disc 20 disposed in an equipotential plane therein so as not to appreciably alter the fundamental resonant frequency of the resonator, and an electron discharge device, separable as a unit from the resonator 10, projecting through an aperture 11 in the resonator wall 12 so that the anode 31 is connected to the conductive disc 20 ; the grid 32 is connected to the apertured resonator wall 12, and the cathode 33 is outside the resonator 10, and further means-a coaxial line resonator 40, 41-is provided for coupling the grid 32 and cathode 33. The grid and anode contacts are by way of resilient fingers 13, 22. The resonator 10 is preferably a right circular cylinder of diameter greater than the height, as shown, and the upper wall 14 thereof carries a threaded bushing 15 engaged by a threaded plunger 16 for tuning ; the conductive disc 20 is supported from the resonator walls by insulating fingers 21. Anode potential is A supplied via lead 48 and - choke 49, a bye- 4 pass condenser structure 48' being provided where the lead 48 enters the resonator ; an output coupling loop 53 is provided. The grid-cathode resonator 40, 41 engages the cathode 33 through the condenser 36, 37, and A is tuned to a length of - by an adjustable 4 plunger 42. The tuning devices 16, 42, may be controlled together through a suitable mechanical linkage. A conductive probe 51 carried by a movable insulating rod 52 provides feed-back if the device is to be used as an oscillator ; alternatively, the device may be used as an amplifier or in repeater circuits, in which case the probe 51 is dispensed with. The slight shift of operating frequency due to the presence of part of the discharge device inside the resonator 10 may be compensated by providing the lower wall 12 thereof with a central recessed portion, Fig. 2 (not shown), so as to decrease the capacity between the wall 12 and the conductive disc 20. A prior art device in which a triode valve is wholly enclosed within a cylindrical cavity resonator and is supported by a conductive cathode disc secured to the resonator walls through suitable insulating supports is referred to. The Specification as open to inspection under Sect. 91 describes modifications in which the conductive means 20 is cylindrical so that the resonator 10 is essentially a coaxial transmission line #/2 in length and open-circuited at both 2 ends, Fig. 4 (Cancelled, not shown). One or two L-shaped feed-back probes 51 may be used, Figs. 6, 7 (Cancelled, not shown). A ring with or without an upturned flange may be connected to the lower end of the cylindrical conductive means 20 so as to effectively increase the anode-grid capacitance. The forms of the tuning plunger 16 and of the byepass condenser 48<1> may also be modified. This subject-matter does not appear in the Specification as accepted.